The objective of the research is to develop highly sensitive, quantitative and facile assays for measuring DNA damage induced by reactive oxygen species (ROS). ROS have been implicated in aging, cancer and several neurodegenerative diseases. Initially three specific ROS-induced DNA lesions will be of particular interest, namely, the formamido remnant of pyrimidine bases, the thymine glycol lesion and the 6-hydroxy-5, 6-dihydrothymine lesion. These lesions will be measured in the form of modified dinucleosides obtained from enzymatic digests of DNA. The method of detection will be by 32P-post labeling. The chief technological component of the undertaking will be the synthesis of modified dimers for use as carriers and internal standards. These carriers are necessary for selectivity and unequivocal identification of the lesions of interest. The internal standards are required for quantification of the lesions. These materials will be offered in kits that should make the detection of ROS-induced DNA damage convenient, sensitive and straightforward. It is anticipated that the availability of these kits will facilitate research on the relationship between ROS and disease. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE